Whisk together the melted butter, brown sugar, granulated sugar, and vanilla extract.
Add in the eggs one at a time and whisk each one until fully incorporated and the batter starts to get lighter in color. To get crinkly brownie tops, be sure to whisk the sugar and eggs for at least 4-5 minutes.
Fold in the cocoa powder, flour, espresso powder, and salt and mix until the batter is just combined.
Then gently fold in the chocolate chips if desired.
Cut a parchment paper sling slightly smaller than the width of the cake pan and make sure it fits flatly in the bottom. Then lightly spray the bottom and sides of the pan with a vegetable oil based spray. Place you parchment paper sling in the bottom of the pan and smooth it out so that it sticks to the pan spray (you can use metal binder clips to secure it to the pan). After baking you’ll be able to just slide the brownies right out of the pan!
Pour the batter into your prepared baking pan.
Bake at 350°F for 30-40 minutes or until an inserted knife comes out mostly clean.
Remove from the oven and let fully cool in the pan.
Once the brownies are cool, use the edges of the parchment paper to slide the brownies out of the pan.
Chocolate Ganache Frosting
Place the heavy cream in a microwave safe bowl and microwave for 1-2 minutes or until hot to the touch but not boiling. Pour over the chopped chocolate and let sit for about two minutes.
Using a spatula, gently mix until the chocolate is fully melted and the ganache is fully combined and smooth.
Let sit at room temperature until is has thickened enough to hold its shape but is still spreadable (this can take a while, so I usually make the ganache while the brownies are baking).
Once the brownies are fully cool, scoop dollops of thickened ganache over the surface of the brownies. Then gently smooth into an even layer and make swirls in the frosting using the back of a spoon.
Sprinkle the frosted brownies with fun chocolate sprinkles if desired!
Notes
It's better to undercook the brownies slightly, than overcook them! Brownies will dry out quick, so it's best to err on the side of caution when baking brownies! Bake just until an inserted toothpick comes out mostly clean but still a tad gooey. If you aren't sure, just go ahead and take them out because they'll continue to firm up as they cool. Note: the larger the pan, the less time the brownies will take to cook.Be patient and let them cool. Warm brownies fresh out of the oven are delish, I know. But it's best to let them fully cool before digging in. The brownies will be less likely to crumble when you cut them and the center is more likely to be fully cooked while still being perfectly fudgy.Note: The square cake pans I use are between 2 ¼ and 2 ½ inches deep (so that you can get those super thick brownies). So if your pan happens to be shallower, you might end up with a little too much batter. So instead you can also bake these brownies in a 9x13 inch pan, just note the brownies will be much thinner than the photos.